The word(s) "day" appears 704 time(s) in 579 verse(s) in Quran in Mohsin Khan translation.

(331) Say: "Our Lord will assemble us all together (on the day of Resurrection), then He will judge between us with truth. And He is the Just Judge, the All-Knower of the true state of affairs [Tafsir Ibn Kathir]

(332) And they say: "When is this promise (i.e. the day of Resurrection) if you are truthful?"

(333) Say (O Muhammad صلى الله عليه وسلم): "The appointment to you is for a day, which you cannot put back for an hour (or a moment) nor put forward."

(334) Those who were deemed weak will say to those who were arrogant: "Nay, but it was your plotting by night and day: when you ordered us to disbelieve in Allah and set up rivals to Him!" And each of them (parties) will conceal their own regrets (for disobeying Allah during this worldly life), when they behold the torment. And We shall put iron collars round the necks of those who disbelieved. Are they requited aught except what they used to do?

(335) And (remember) the day when He will gather them all together, then He will say to the angels: "Was it you that these people used to worship?"

(336) So Today (i.e. the day of Resurrection), none of you can profit or harm one another. And We shall say to those who did wrong [i.e. worshipped others (like the angels, jinn, prophets, saints, righteous persons) along with Allah]: "Taste the torment of the Fire which you used to belie.

(337) He merges the night into the day (i.e. the decrease in the hours of the night is added to the hours of the day), and He merges the day into the night (i.e. the decrease in the hours of the day is added to the hours of the night). And He has subjected the sun and the moon: each runs its course for a term appointed. Such is Allah, your Lord; His is the kingdom. And those, whom you invoke or call upon instead of Him, own not even a Qitmir (the thin membrane over the date-stone).

(338) If you invoke (or call upon) them, they hear not your call; and if (in case) they were to hear, they could not grant it (your request) to you. And on the day of Resurrection, they will disown your worshipping them. And none can inform you (O Muhammad صلى الله عليه وسلم) like Him Who is the All-Knower (of everything).

(339) And a sign for them is the night. We withdraw therefrom the day, and behold, they are in darkness.

(340) It is not for the sun to overtake the moon, nor does the night outstrip the day. They all float, each in an orbit.